Here is the full list of all 24 Monster High: New Ghoul in School achievements.
Save the School!
All other Achievements Complete.
Upgrade the Casketball Court.
Complete Fashion Club Events.
Obtain All Clothing Items.
Complete Standalone Events.
Complete Cooking Club Events.
Collect all Spirit Spiders.
Upgrade the Creepateria.
Complete Comic Book Club Events.
Complete Robotics Club Events.
Complete a Fundraising Event.
Complete Environmental Club Events.
Leave for school with a Tidy Room.
Collect all Cheer Steps.
Have over 1000 Spirit Coins.
Find all the Shortcuts.
Meet all the characters in Monster High.
Collect all Dusty Pennants.
Ring the Bell in the Bell Tower.
Purchase Clothing Online.
Complete first Fearleading Event.
Find and use a Locker Code.
Complete first Council Event.